Site aggregator, legal issues?

Question

Law in IT

There is an idea to make an interesting (as it seems to me) aggregator kinopoisk.ru and several similar sites.
The service is not public, i.e. install an aggregator on your site, and according to certain criteria, it gives you certain information personally.
Interested in the legal aspects of creating such a system for personal use and subsequent publication under the GPL of such a license.
Do I need to make links to all sites information is taken from? Do I need permission from the site owners? Any other pitfalls?

Answer 1

Look, for example, at the legal aspects of the work of the Yandex. News .
Information materials of any types and forms of presentation, including texts, images, photographs, audio and video materials (in the text - "Information") posted on the Service, or available through links to other sites posted on the Service, are provided by the Partners of the Service, the list which is given at: news.yandex.ru/smi/.The rights to the specified Information belong to the Service Partners or other copyright holders (information holders). The information is available on the service only in citation mode for informational purposes. Users do not receive any rights to use the Information outside the scope of the possibilities provided by the Service, and are fully responsible to the copyright holder for their illegal use.